Compressor

ABSTRACT

A compressor includes a rotary shaft, a housing in which a suction port through which a suction fluid is drawn in and a discharge port through which a compression fluid is discharged are formed, and that houses the rotary shaft, and compression chambers. The suction fluid is drawn into the compression chambers. Respective volumes of the compression chambers are periodically changed with rotation of the rotary shaft. The phases of volume changes of the compression chambers are mutually shifted. The compressor includes a communication mechanism switched between a communicating state in which the compression chambers communicate with each other, and a non-communicating state in which the compression chambers do not communicate with each other.

BACKGROUND

The present disclosure relates to a compressor.

Japanese Laid-Open Patent Publication No. 2015-28313 describes acompressor including a rotary shaft, rotors rotated with rotation of therotary shaft, a vane rotated with rotation of the rotors, and a firstcompression chamber and a second compression chamber communicating witheach other. In this compressor, fluid is compressed in the compression.chambers by the rotation of the rotors and the vane. Particularly,first, the fluid is drawn in from the outside and compressed in thefirst compression chamber. Then, when the first compression chamberapproaches its minimum volume, an intermediate pressure fluid compressedin the first compression chamber flows into an intermediate pressurechamber. Thereafter, the intermediate pressure fluid flows into thesecond compression chamber from the intermediate pressure chamber, andis further compressed in the second compression chamber.

In the above-described two-step compression method in which one cycle isuntil the intermediate pressure fluid compressed in the firstcompression chamber is further compressed in the second compressionchamber, the fluid is drawn in by only the first compression chamber.Therefore, the volume of the second compression chamber does notcontribute to the volume of the entire compressor.

In the two-step compression method, the situation may occur where thevolume locally becomes small during one cycle. For example, as shown inFIG. 18, the fluid flows into the second compression chamber from thefirst compression chamber, so that the intermediate pressure fluid isdrawn in by the second compression chamber in the stage in which thefirst compression chamber approaches its minimum volume. In this case,when the volume of the second compression chamber is small at the timingat which the fluid flows in from the first compression chamber, thevolumes of the two compression chambers become small. Therefore, thevolume of the entire compressor obtained by combining the twocompression chambers becomes locally small while the above-mentionedcycle is repeated. When such a situation occurs, over compressionoccurs, and the efficiency is deteriorated.

SUMMARY

An object of the present disclosure is to provide a compressor that canreliably compress fluid by using two compression chambers.

In accordance with a first aspect of the present disclosure, acompressor is provided that includes: a rotary shaft; a housing housingthe rotary shaft and having a suction port through which a suction fluidis drawn in and a discharge port through which a compression fluid isdischarged; a first compression chamber and a second compression chamberformed to introduce therein the suction fluid, respective volumes of thefirst compression chamber and the second compression chamber beingperiodically changed with rotation of the rotary shaft, and phases ofchanges of the respective volumes being mutually shifted; and acommunication mechanism switched between a communicating state in whichthe first compression chamber and the second compression chambercommunicate with each other, and a non-communicating state in which thefirst compression chamber and the second compression chamber do notcommunicate with each other. A cycle movement is performed that includesparallel compression operation in which compression of fluid isperformed in the compression chambers in the communicating state.

Other aspects and advantages of the present disclosure will becomeapparent from the following description, taken in conjunction with theaccompanying drawings, illustrating exemplary embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure may be understood by reference to the followingdescription together with the accompanying drawings:

FIG. 1 is a cross-sectional view showing an outline of a compressor;

FIG. 2 is an exploded perspective view of a main configuration;

FIG. 3 is an exploded perspective view of the main configuration seenfrom the opposite side from FIG. 2;

FIG. 4 is a partial enlarged view of FIG. 1;

FIG. 5 is a cross-sectional view of the rotors, a vane, and a rearcylinder;

FIG. 6 is cross-sectional view taken along line 6-6 in FIG. 5;

FIG. 7 is a bottom view, with a part cut away, of the main configurationin a state where a part of the cylinders;

FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 4;

FIG. 9 is a development view showing rotors and a vane in the state ofFIG. 4;

FIG. 10A is a cross-sectional view showing the rotors arranged atangular positions different from those in FIG. 4, and theirsurroundings;

FIG. 10B is a development view showing the situation of the rotors andthe vane in the state of FIG. 10A;

FIG. 11A is a graph showing the volume change of compression chambersand the entire compressor, etc. in a first embodiment;

FIG. 11B is a time chart showing the state of an open/close portion inthe first embodiment;

FIG. 11C is a time chart showing the state of a communication mechanismin the first embodiment;

FIG. 12 is a cross-sectional view showing the communication mechanism ina second embodiment;

FIG. 13 is a cross-sectional view showing the communication mechanism inthe second embodiment;

FIG. 14A is a graph showing the volume change of the compressionchambers and the entire compressor, etc. in the second embodiment;

FIG. 14B is a time chart showing the state of the open/close portion inthe second embodiment;

FIG. 14C is a time chart showing the state of the communicationmechanism in the second embodiment;

FIG. 15 is a schematic diagram showing another example of thecommunication mechanism;

FIG. 16 is a schematic diagram showing another example of thecommunication mechanism;

FIG. 17 is a schematic diagram showing another example of theconfiguration for introducing a suction fluid into a rear compressionchamber; and

FIG. 18 is a graph showing the volume change of the two-step compressionmethod.

DETAILED DESCRIPTION First Embodiment

A compressor according to a first embodiment will now be described withreference to the drawings. The compressor of the first embodiment ismounted on and used in a vehicle. The compressor is used for a vehicleair-conditioner. The fluid to be compressed by the compressor isrefrigerant including oil. FIGS. 1 and 4 show side views of a rotaryshaft 12 and the rotors 60 and 80.

As shown in FIG. 1, a compressor 10 includes a housing 11, a rotaryshaft 12, an electric motor 13, an inverter 14, a front cylinder 40, arear cylinder 50, a front rotor 60 as a first rotor, and rear rotor 80as a second rotor. The housing 11 has a generally tubular shape, andincludes a suction port 11 a through which a suction fluid is drawn infrom the outside, and a discharge port 11 b from which the fluid isdischarged. The rotary shaft 12, the electric motor 13, the inverter 14,the cylinders 40 and 50, and the rotors 60 and 80 are housed in thehousing 11.

The housing 11 includes a front housing member 21, a rear housing member22, and an inverter cover 23. The front housing member 21 has a tubularshape with a closed end, and is opened toward the rear housing member22. The suction port 11 a is provided at a position between an open endand the bottom in a side wall portion of the front housing member 21.However, the position of the suction port 11 a is arbitrary. The rearhousing member 22 has a tubular shape with a closed end, and is openedtoward the front housing member 21. The discharge port 11 b is providedin a side surface of the bottom of the rear housing member 22. Theposition of the discharge port 11 b is arbitrary.

The front housing member 21 and the rear housing member 22 are unitizedwith their openings opposed to each other. The inverter cover 23 isarranged in the bottom of the front housing member 21, which is theopposite side from the rear housing member 22. The inverter cover 23 isfixed to the front housing member 21 with being butted to the bottom ofthe front housing member 21.

The inverter 14 is housed in the inverter cover 23. The inverter 14drives the electric motor 13. The rotary shaft 12 is supported by thehousing 11 in a rotatable state. A ring-shaped first bearing holdingpart 31 protruding from the bottom is provided in the bottom of thefront housing member 21. A first radial bearing 32, which rotationallysupports a first end of the rotary shaft 12, is provided inside in theradial direction of the first bearing holding part 31. A ring-shapedsecond bearing holding part 33 protruding from the bottom is provided inthe bottom of the rear housing member 22. A second radial bearing 34 isalso provided inside the radial direction of the second bearing holdingpart 33. The second radial bearing 34 rotationally supports the secondend of the rotary shaft 12, which is on the opposite side from the firstend. The axial direction Z of the rotary shaft 12 matches the axialdirection of the housing 11.

As shown in FIGS. 1 to 4, the front cylinder 40 houses the front rotor60. The front cylinder 40 has a tubular shape with a closed end formedto be somewhat smaller than the rear housing member 22. The frontcylinder 40 is opened toward the bottom of the rear housing member 22.The front cylinder 40 includes a front cylinder bottom 41, and a frontcylinder side wall portion 42 extending from the front cylinder bottom41 toward the rear housing member 22. The front cylinder side wallportion 42 is a first cylindrical portion, and enters inside the rearhousing member 22.

As shown in FIGS. 3 and 4, the front cylinder 40 includes a frontcylinder inner circumferential surface 43 as a first innercircumferential surface. The front cylinder inner circumferentialsurface 43 is a cylindrical surface extending in an axial direction Z.The front cylinder 40 further includes a front large diameter surface 44whose diameter is larger than the front cylinder inner circumferentialsurface 43. The front large diameter surface 44 is provided in a tippart (open end) of the front cylinder side wall portion 42. A frontstepped surface 45 is formed between the front cylinder innercircumferential surface 43 and the front large diameter surface 44.

A bulged part 46 projecting to the radially outside of the rotary shaft12 is provided in the front cylinder side wall portion 42. The bulgedpart 46 is provided in the base end of the front cylinder side wallportion 42, i.e., near the front cylinder bottom 41. The front housingmember 21 and the rear housing member 22 are unitized with the bulgedpart 46 being inserted therebetween. The housings 21 and 22 regulate theposition gap in the axial direction Z of the front cylinder 40.

As shown in FIG. 4, the front cylinder bottom 41 has a stepped shape inthe axial direction Z. The front cylinder bottom 41 includes a firstbottom 41 a arranged on the central side, and a second bottom 41 barranged radially outside of the first bottom 41 a, and closer to therear housing member 22 than the first bottom 41 a. A front insertionhole 41 c, to which the rotary shaft 12 can be inserted, is formed inthe first bottom 41 a. The rotary shaft 12 is inserted into the frontinsertion hole 41 c.

As shown in FIG. 1, the front housing member 21 and the front cylinderbottom 41 form a motor chamber A1, and house the electric motor 13 inthe motor chamber A1. The electric motor 13 rotates the rotary shaft 12in the direction indicated by an arrow M when driving power is suppliedfrom the inverter 14. The suction port 11 a is provided in the fronthousing member 21 that forms the motor chamber A1. Therefore, thesuction fluid drawn in from the suction port 11 a is introduced into themotor chamber A1. That is, the suction fluid exists in the motor chamberA1.

Within the compressor 10, the inverter 14, the electric motor 13, andthe rotors 60 and 80 are arranged in order in the axial direction Z. Theposition of each of these parts is arbitrary, and the inverter 14 may bearranged radially outside of the electric motor 13.

As shown in FIGS. 2 to 4, the rear cylinder 50 has a tubular shape witha closed end. The rear cylinder 50 is opened toward the bottom of therear housing member 22. The rear cylinder 50 is formed to be somewhatsmaller than the front cylinder 40, and is housed in the rear housingmember 22. The rear cylinder 50 is fitted to the front cylinder 40 withthe open end of the rear cylinder 50 being butted to the bottom of therear housing member 22.

The rear cylinder 50 includes an intermediate wall portion 51 formingthe bottom of the rear cylinder 50, and a rear cylinder side wallportion 55 extending in the axial direction Z toward the rear housingmember 22 from the intermediate wall portion 51. The rear cylinder sidewall portion 55 and the intermediate wall portion 51 correspond to asecond cylindrical portion and a wall portion, respectively.

As shown in FIG. 4, the intermediate wall portion 51 is arranged so thatits wall thickness direction matches the axial direction Z. Therefore,the intermediate wall portion 51 includes a first wall surface 52 and asecond wall surface 53 that are perpendicular to the axial direction Z.The intermediate wall portion 51 has a ring shape, and is fitted to thefront cylinder 40. A wall through-hole 54 extending through the axialdirection Z is formed in the intermediate wall portion 51. The wallthrough-hole 54 is a through-hole having a larger diameter than therotary shaft 12. The rotary shaft 12 is inserted into the wallthrough-hole 54.

The rear cylinder side wall portion 55 has a cylindrical shape extendingin the axial direction Z, and includes a rear cylinder innercircumferential surface 56 as a second inner circumferential surface,and a rear cylinder outer circumferential surface 57. The rear cylinderinner circumferential surface 56 is a cylindrical surface having asmaller diameter than the front cylinder inner circumferential surface43. Therefore, the rear cylinder inner circumferential surface 56 isarranged inside in the radial direction of the front cylinder innercircumferential surface 43. The rear cylinder outer circumferentialsurface 57 includes a several cylindrical surfaces having differentdiameters, and thus has a stepped shape. The rear cylinder outercircumferential surface 57 includes a first part surface 57 a, a secondpart surface 57 b whose diameter is larger than the first part surface57 a, and a third part surface 57 c whose diameter is larger than thesecond part surface 57 b.

The first part surface 57 a contacts the front cylinder innercircumferential surface 43. The second part surface 57 b contacts thefront large diameter surface 44. The third part surface 57 c is flushwith the outer circumferential surface of the front cylinder side wallportion 42. A first rear stepped surface 58 formed between the partsurfaces 57 a and 57 b contacts a front stepped surface 45, and a secondrear stepped surface 59 formed between the part surfaces 57 b and 57 ccontacts the open end of the front cylinder 40.

As shown in FIG. 4, the front cylinder bottom 41, the front cylinderinner circumferential surface 43, and the first wall surface 52 form afront housing chamber A2 that houses the front rotor 60. The fronthousing chamber A2 has a generally cylindrical shape. The inside bottomsurface of the rear housing member 22, the rear cylinder innercircumferential surface 56, and the second wall surface 53 form a rearhousing chamber A3 that houses the rear rotor 80. The rear housingchamber A3 has a generally cylindrical shape.

Since the diameter of the rear cylinder inner circumferential surface 56is smaller than the diameter of the front cylinder inner circumferentialsurface 43, the rear housing chamber A3 is smaller than the fronthousing chamber A2, and the volume of the rear housing chamber A3 issmaller than the volume of the front housing chamber A2. The housingchambers A2 and A3 are divided by the intermediate wall portion 51. Therotors 60 and 80 are opposed to each other in the axial direction Z,with the intermediate wall portion 51 being arranged therebetween.

The rotary shaft 12 and the rotors 60 and 80 have the same axis. Thatis, the compressor 10 has the structure for axial center movement,instead of eccentric movement. The circumferential directions of therotors 60 and 80 match the circumferential direction of the rotary shaft12, the radial directions of the rotors 60 and 80 match the radialdirection R of the rotary shaft 12, and the axial directions of therotors 60 and 80 match the axial direction Z of the rotary shaft 12.Therefore, the circumferential direction, the radial direction R, andthe axial direction Z of the rotary shaft 12 may be properly read as thecircumferential direction, the radial direction, and the axial directionof the rotors 60 and 80.

As shown in FIGS. 2 to 5, the front rotor 60 has a ring shape, andincludes a front through-hole 61 into which the rotary shaft 12 can beinserted. The front through-hole 61 has the same diameter as the rotaryshaft 12. The front rotor 60 is attached to the rotary shaft 12 with therotary shaft 12 being inserted into the front through-hole 61.

The front rotor 60 rotates with the rotation of the rotary shaft 12.That is, the front rotor 60 integrally rotates with the rotary shaft 12.The configuration for the front rotor 60 to integrally rotate with therotary shaft 12 is arbitrary, and there are, for example, aconfiguration in which the front rotor 60 is fixed to the rotary shaft12, and a configuration in which the front rotor 60 is engaged with theouter circumference of the rotary shaft 12.

A front rotor outer circumferential surface 62, which is an outercircumferential surface of the front rotor 60, is a cylindrical surfacehaving the same axis as the rotary shaft 12. The diameter of the frontrotor outer circumferential surface 62 is the same as that of the frontcylinder inner circumferential surface 43. There may be a slight gapbetween the front rotor outer circumferential surface 62 and the frontcylinder inner circumferential surface 43.

The front rotor 60 includes a front rotor surface 70 as a first rotorsurface opposed to first wall surface 52. The front rotor surface 70 hasa ring shape. The front rotor surface 70 includes a first front flatsurface 71 and a second front flat surface 72 that are perpendicular tothe axial direction Z, and first curving surfaces, which are a pair offront curving surfaces 73 connecting the front flat surfaces 71 and 72.The first and second front flat surfaces 71 and 72 correspond to firstand second flat surfaces, respectively.

As shown in FIG. 5, the front flat surfaces 71 and 72 are shifted to theaxial direction Z. The second front flat surface 72 is arranged closerto the first wall surface 52 than the first front flat surface 71. Thesecond front flat surface 72 contacts the first wall surface 52.Additionally, the front flat surfaces 71 and 72 are separated in thecircumferential direction of the front rotor 60, and are shifted 180degrees. The front flat surfaces 71 and 72 have sectoral shapes. In thefollowing description, the circumferential direction positions of therotors 60 and 80 are called the angular positions.

Each of the pair of front curving surfaces 73 has a sectoral shape. Asshown in FIG. 3, the pair of front curving surfaces 73 oppose to thedirection perpendicular to the axial direction Z and the direction alongwhich the front flat surfaces 71 and 72 are arranged. Both of the frontcurving surfaces 73 have an identical shape. Each of the pair of frontcurving surfaces 73 connects the front flat surfaces 71 and 72. One ofthe pair of front curving surfaces 73 connects one ends in thecircumferential directions of the front flat surfaces 71 and 72, and theother connects the other ends of in the circumferential directions ofthe front flat surfaces 71 and 72.

As shown in FIG. 3, let the angular position of the boundary partbetween the front curving surface 73 and the first front flat surface 71be a first angular position θ1, and let the angular position of theboundary part between the front curving surface 73 and the second frontflat surface 72 be a second angular position θ2. In FIG. 3, each of theangular positions θ1 and θ2 are indicated by broken lines. However,actually, the boundary parts are continued smoothly.

The front curving surface 73 is a curving surface displaced in the axialdirection Z in accordance with the angular position of the front rotor60. The front curving surface 73 is curved in the axial direction Z soas to be gradually closer to the first wall surface 52 from the firstangular position 81 to the second angular position θ2. Therefore, asshown in FIG. 6, when the front curving surface 73 is cut at a middleposition, the front curving surface 73 is located at a position that isbetween the front flat surfaces 71 and 72 in the axial direction Z, andthat is separated from the first wall surface 52. The front curvingsurface 73 is curved in the axial direction Z so as to be graduallycloser to or distant from the first wall surface 52 between twoarbitrary angular positions that are mutually separated in thecircumferential direction, which are not limited to the first angularposition θ1 and the second angular position θ2.

As shown in FIG. 7, the front curving surface 73 includes a frontconcave surface 73 a that is curved in the axial direction Z so as to beconcave toward the first wall surface 52, and a front convex surface 73b that is curved in the axial direction Z so as to be convex toward thefirst wall surface 52. The front concave surface 73 a is arranged closerto the first front flat surface 71 than the second front flat surface72, and the front convex surface 73 b is arranged closer to the secondfront flat surface 72 than the first front flat surface 71. The frontconcave surface 73 a is connected to the front convex surface 73 b. Thefront curving surface 73 is a curving surface with an inflection point.The angle range occupied by the front convex surface 73 b may be thesame as or different from the angle range occupied by the front concavesurface 73 a. The position of the inflection point is arbitrary.

As shown in FIGS. 2 to 5, the rear rotor 80 has a ring shape, andincludes a rear through-hole 81 into which the rotary shaft 12 can beinserted. The rear through-hole 81 has the same diameter as the rotaryshaft 12. The rotary shaft 12 is inserted into the rear through-hole 81,and the rear rotor 80 is engaged with the front rotor 60. The engagementof the front rotor 60 and the rear rotor 80 will be described later. Therear rotor 80 rotates with the rotation of the rotary shaft 12. That is,the rear rotor 80 integrally rotates with the rotary shaft 12. Theconfiguration for the rear rotor 80 to integrally rotate with the rotaryshaft 12 is arbitrary, and there are, for example, a configuration inwhich the rear rotor 80 is fixed to the rotary shaft 12, and aconfiguration in which the rear rotor 80 is engaged with the outercircumference of the rotary shaft 12.

As shown in FIGS. 4 to 6, the rear rotor 80 is formed to be smaller thanthe front rotor 60. The diameter of the rear rotor 80 is smaller thanthe diameter of the front rotor 60. A rear rotor outer circumferentialsurface 82, which is an outer circumferential surface of the rear rotor80, is a cylindrical surface having a smaller diameter than the frontrotor outer circumferential surface 62. The diameter of the rear rotorouter circumferential surface 82 is the same as that of the rearcylinder inner circumferential surface 56. There may be a slight gapbetween the rear rotor outer circumferential surface 82 and the rearcylinder inner circumferential surface 56.

As shown in FIGS. 2 and 4, the rear rotor 80 includes a rear rotorsurface 90 as a second rotor surface opposed to the second wall surface53. The rear rotor surface 90 has a ring shape. The rear rotor surface90 includes a first rear flat surface 91 and a second rear flat surface92 that are perpendicular to the axial direction Z, and second curvingsurfaces, which are a pair of rear curving surfaces 93 that connect therear flat surfaces 91 and 92.

As shown in FIG. 5, the rear flat surfaces 91 and 92 are shifted in theaxial direction Z. The second rear flat surface 92 is arranged closer tothe second wall surface 53 than the first rear flat surface 91. Thesecond rear flat surface 92 contacts the second wall surface 53. Therear flat surfaces 91 and 92 are separated in the circumferentialdirection of the rear rotor 80, and are shifted 180 degrees. The rearflat surfaces 91 and 92 have sectoral shapes.

Each of the pair of rear curving surfaces 93 has a sectoral shape. Thepair of rear curving surfaces 93 oppose to the direction perpendicularto the axial direction Z and the direction along which the rear flatsurfaces 91 and 92 are arranged. One of the pair of the rear curvingsurfaces 93 connects one ends in the circumferential direction of therear flat surfaces 91 and 92, and the other connects the other ends inthe circumferential direction of the rear flat surfaces 91 and 92.

The rotor surfaces 70 and 90 are arranged to be opposed to each other inthe axial direction Z with the intermediate wall portion 51therebetween. The separation distance between the rotor surfaces 70 and90 is constant irrespective of the angular positions and thecircumferential direction positions of the rotor surfaces 70 and 90. Asshown in FIG. 5, the first front flat surface 71 and the second rearflat surface 92 are opposed to each other in the axial direction Z, andthe second front flat surface 72 and the first rear flat surface 91 areopposed to each other in the axial direction Z, respectively. The shiftamount in the axial direction Z between the front flat surfaces 71 and72 is the same as the shift amount between the rear flat surfaces 91 and92. The shift amount in the axial direction Z between the front flatsurfaces 71 and 72, and the shift amount between the rear flat surfaces91 and 92 are called the shift amount L1.

As shown in FIGS. 4, 6 and 7, the degree of curvature of the frontcurving surface 73 is the same as the degree of curvature of the rearcurving surface 93. That is, the front curving surface 73 and the rearcurving surface 93 are curved in the same direction, so that theseparation distance are not changed in accordance with the angularpositions of the curving surfaces. Accordingly, the separation distancebetween the rotor surfaces 70 and 90 is constant irrespective of theangular positions. The rotor surfaces 70 and 90 have an identical shapeexcept that they have different diameters. Since the shapes of the firstrear flat surface 91, the second rear flat surface 92, and the rearcurving surface 93 are the same as those of the first front flat surface71, the second front flat surface 72, and the front curving surface 73,a detailed description is omitted.

As shown in FIGS. 2 to 5, the compressor 10 includes a vane 100, and avane groove 110 into which the vane 100 is inserted. The vane 100contacts the rotors 60 and 80, and thus moves in the axial direction Zwith the rotation of the rotors 60 and 80. The vane 100 is arrangedbetween the rotors 60 and 80, i.e., between the rotor surfaces 70 and90, with the surface of the vane 100 being perpendicular to thecircumferential direction of the rotary shaft 12. The vane 100 has atabular shape having the thickness in the direction perpendicular to theaxial direction Z.

The vane 100 has a first vane end 101 and a second vane end 102 as theopposite ends in the axial direction Z. The first vane end 101 contactsthe front rotor surface 70, and the second vane end 102 contacts therear rotor surface 90. Although the shapes of the vane ends 101 and 102are arbitrary, may be curved so as to be convex toward the rotorsurfaces 70 and 90.

As shown in FIGS. 2 to 4, the vane groove 110 is formed in the rearcylinder 50. The vane groove 110 is formed over both of the intermediatewall portion 51 and the rear cylinder side wall portion 55. The vanegroove 110 is a slit extending through the rear cylinder 50 in a radialdirection R. The opposite ends of the vane groove 110 in the radialdirection R are opened. The vane groove 110 extends through theintermediate wall portion 51. The end on the front rotor 60 side of theopposite ends of the vane groove 110 in the axial direction Z is opened.The opposite side surfaces of the vane groove 110 are opposed tocorresponding surfaces of the opposite surfaces of the vane 100. Thewidth of the vane groove 110, i.e., the separation distance between theside surfaces of the vane groove 110, is the same as or slightly largerthan the thickness of the vane 100.

As shown in FIG. 4 and FIG. 7, the vane groove 110 extends in the axialdirection Z from the intermediate wall portion 51 to the middle of therear cylinder side wall portion 55. The vane groove 110 also existsradially outside of the rear rotor 80. The length in the axial directionZ of the vane groove 110 is the same as or longer than the length in theaxial direction Z of the vane 100. By inserting the vane 100 into thevane groove 110, the movement of the vane 100 in the circumferentialdirection is restricted. In contrast, it is permitted for the vane 100to move in the axial direction Z along the vane groove 110.

According to this configuration, when the rotors 60 and 80 rotate, thevane 100 moves in the axial direction Z while sliding on the rotorsurfaces 70 and 90. Accordingly, the first vane end 101 of the vane 100enters into the front housing chamber A2, or the second vane end 102enters into the rear housing chamber A3. In contrast, the vane 100contacts both side surfaces of the vane groove 110, and thus themovement in the circumferential direction is restricted. Therefore, evenif the rotors 60 and 80 are rotated, the vane 100 is not rotated.

The vane groove 110 allows the arrangement of the vane 100 over thehousing chambers A2 and A3 and restricts the rotation of the vane 100,even if the rotors 60 and 80 are rotated. The movement distance of thevane 100 is the displacement amount (the shift amount L1) in the axialdirection Z between the front flat surfaces 71 and 72 (or between therear flat surfaces 91 and 92). Additionally, during the rotation of therotors 60 and 80, the vane 100 continues to contact the rotor surfaces70 and 90. That is, the vane 100 does not contact intermittently, anddoes not periodically repeat separation and contact.

As shown in FIG. 6, the curving surfaces 73 and 93 may be slightlyrecessed from the outside toward the inside of the radial direction R aslong as they contact the vane ends 101 and 102. In this case, the vaneends 101 and 102 contact from the radially inner end toward the radiallyouter end of the curving surfaces 73 and 93, while slightly shifting thecontact position with the curving surfaces 73 and 93 in thecircumferential direction. This is not a limitation, and the curvingsurfaces 73 and 93 may extend straight in the direction perpendicular tothe axial direction Z, so that a displacement along the radial directionR at an identical angle position may not occur. That is, as long as theseparation distance between the curving surfaces 73 and 93 is constantat the angular position of the same radius, the separation distance maybe slightly changed along the radial direction R, or may be constant.

As shown in FIG. 4, a front compression chamber A4 is formed in thefront housing chamber A2 by the front rotor 60 (the front rotor surface70), the front cylinder inner circumferential surface 43, and the firstwall surface 52. A rear compression chamber A5 is formed in the rearhousing chamber A3 by the rear rotor 80 (the rear rotor surface 90), therear cylinder inner circumferential surface 56, and the second wallsurface 53. The compression chambers A4 and A5 are opposed to each otherin the axial direction Z with the intermediate wall portion 51 inbetween. In the compression chambers A4 and A5, with the rotation of therotary shaft 12, their volumes are periodically changed, andsuction/compression of fluid are performed by the vane 100. That is, thevane 100 produces a volume change in the compression chambers A4 and A5.This point will be described later.

Since the front rotor 60 is formed to be larger than the rear rotor 80,the front compression chamber A4 is larger than the rear compressionchamber A5. That is, the maximum volume of the front compression chamberA4 is larger than the maximum volume of the rear compression chamber A5.As shown in FIGS. 2 and 3, an introduction port 111 for introducing thesuction fluid in the motor chamber A1 into the front compression chamberA4 is formed in the front rotor 60. The introduction port 111 has anoval shape that is long in the radial direction R. The shape of theintroduction port 111 is not limited to this, and is arbitrary.

The introduction port 111 extends through the front rotor 60 in theaxial direction Z. The introduction port 111 is arranged near theradially outer end of the front rotor 60. The introduction port 111 isarranged at a position where the introduction port 111 communicates withthe front compression chamber A4 at the phase at which the volume of thefront compression chamber A4 becomes large, and does not communicatewith the front compression chamber A4 at the phase at which the volumeof the front compression chamber A4 becomes small. The introduction port111 is provided near the boundary between the second front flat surface72 and the front curving surface 73, specifically, near the end in thecircumferential direction of the front curving surface 73 close to thesecond front flat surface 72. Further, the introduction port 111 isformed in the front curving surface 73 on the opposite side in therotation direction with respect to the second front flat surface 72.

As shown in FIGS. 2 and 3, communication holes 112 communicating withthe introduction port 111 are formed in the front cylinder 40. Thecommunication holes 112 are provided at the positions corresponding tothe introduction port 111. When seen from the axial direction Z, thecommunication holes 112 are formed at the positions that overlap withthe trajectory of the introduction port 111 when the front rotor 60 isrotated. The communication holes 112 extend in the circumferentialdirection of the rotary shaft 12, and four communication holes 112 areseparated from each other in the circumferential direction. Accordingly,even if the position of the introduction port 111 changes with therotation of the front rotor 60, the communication between theintroduction port 111 and the communication holes 112 is easilymaintained.

A discharge port 113 that discharges the compression fluid compressed inthe rear compression chamber A5 is formed in the rear rotor 80. Thedischarge port 113 extends through the rear rotor 80 in the axialdirection Z. The discharge port 113 is smaller than the introductionport 111. The discharge port 113 is circular. The shape of the dischargeport 113 is not limited to this, and is arbitrary.

The discharge port 113 is arranged at a position where the dischargeport 113 communicates with the rear compression chamber A5 at the phaseat which the volume of the rear compression chamber A5 becomes small,and does not communicate with the rear compression chamber A5 at thephase at which the volume of the rear compression chamber A5 becomeslarge. The discharge port 113 is provided near the boundary between thesecond rear flat surface 92 and the rear curving surface 93,specifically, at the end in the circumferential direction of the rearcurving surface 93 close to the second rear flat surface 92. Further,the discharge port 113 is formed in the rear curving surface 93 that ison the rotation direction side with respect to the second rear flatsurface 92.

When seen from the axial direction Z, the introduction port 111 isarranged on the same side as the discharge port 113, instead of theopposite side from the discharge port 113, on the basis of the centerline passing through the centers of the rotors 60 and 80, and extendingin the direction along which the flat surfaces 71 and 72 are arranged.However, the positions of the introduction port 111 and the dischargeport 113 are arbitrary. A discharge valve that closes the discharge port113 and makes the discharge port 113 open based on application of aspecified pressure may be provided. The discharge valve is notessential.

As shown in FIG. 1, the compressor 10 includes a discharge chamber A6into which the compression fluid discharged from the discharge port 113flows, and a discharge passage 114 that connects the discharge chamberA6 and the discharge port 11 b. The discharge chamber A6 is formed bythe rear cylinder 50 and the rear housing member 22. The dischargechamber A6 is arranged between the discharge port 113 and the rearhousing member 22. When seen from the axial direction Z, the dischargechamber A6 is formed in a ring shape so as to overlap with thetrajectory of the discharge port 113 accompanying the rotation of therear rotor 80. Accordingly, it is possible to limit the situation inwhich the discharge port 113 and the discharge chamber A6 do notcommunicate with each other, depending on the angular position of therear rotor 80. According to this configuration, the fluid dischargedfrom the discharge port 113 is discharged from the discharge port 11 bvia the discharge chamber A6 and the discharge passage 114.

The compressor 10 is configured such that the suction fluid is drawn inby not only the front compression chamber A4 but also by the rearcompression chamber A5. As shown in FIG. 4, the compressor 10 includes arear side suction passage 115 that introduces the suction fluid into therear compression chamber A5, and an open/close portion 116 that opensand closes the rear side suction passage 115. The rear side suctionpassage 115 makes the motor chamber A1 and the rear compression chamberA5 communicate with each other. The rear side suction passage 115 isformed in the housing 11, and extends through the front cylinder 40 andthe rear cylinder 50.

The open/close portion 116 is provided on the rear side suction passage115, and is switched between a closed state in which the rear sidesuction passage 115 is closed, and an open state in which the rear sidesuction passage 115 is opened. In the closed state, the suction fluid inthe motor chamber A1 is restricted from flowing into the rearcompression chamber A5 via the rear side suction passage 115. In theopen state, it is permitted that the suction fluid in the motor chamberA1 flows into the rear compression chamber A5 via the rear side suctionpassage 115. The suction of the suction fluid into the rear compressionchamber A5 is started and stopped by the open/close portion 116. Theconfiguration of the open/close portion 116 is arbitrary, such as aconfiguration using a rotary valve, and a configuration using anelectromagnetic valve.

The compressor 10 includes a communication mechanism 120 that switchesbetween a communicating state in which the compression chambers A4 andA5 communicate with each other, and a non-communicating state in whichthe compression chambers A4 and A5 are not communicating with eachother. A detailed configuration of the communication mechanism 120 isdescribed below.

As shown in FIGS. 2 to 4, the communication mechanism 120 includes afront boss portion 121 as a first boss portion provided in the frontrotor 60, a front rotary valve 122 as a first engagement portion, a rearboss portion 123 as a second boss portion provided in the rear rotor 80,and a rear rotary valve 124 as a second engagement portion. When therotary shaft 12 is rotated, the boss portions 121 and 123 are alsorotated.

The front boss portion 121 protrudes toward the rear rotor 80 from thefront rotor surface 70. The front boss portion 121 protrudes furthertoward the rear rotor surface 90 than the second front flat surface 72.The front boss portion 121 consists of a cylinder provided in theradially inner end of the front rotor surface 70. The rotary shaft 12 isinserted into the front boss portion 121. The outer diameter of thefront boss portion 121 is substantially the same as the diameter of thewall through-hole 54. The front boss portion 121 is fitted to beslidable from the first wall surface 52 to the wall through-hole 54. Thefront boss portion 121 includes an annular front boss tip surface 121 a.

As shown in FIG. 3, the two front rotary valves 122 protrude toward therear rotor 80 from the front boss tip surface 121 a. Two front rotaryvalves 122 are provided at the positions separated in thecircumferential direction and face each other. The front rotary valves122 have sectoral shapes. The inner circumferential surfaces of thefront rotary valves 122 are flush with the inner circumferential surfaceof the front boss portion 121, and contact the outer circumferentialsurface of the rotary shaft 12. The outer circumferential surfaces ofthe front rotary valves 122 are flush with the outer circumferentialsurface of the front boss portion 121.

As shown in FIGS. 2 and 4, the rear boss portion 123 protrudes towardthe front rotor 60 from the rear rotor surface 90. The rear boss portion123 protrudes further toward the front rotor surface 70 than the secondrear flat surface 92. The rear boss portion 123 consists of a cylinderprovided in the radially inner end of the rear rotor surface 90. Therotary shaft 12 is inserted into the rear boss portion 123. The outerdiameter of the rear boss portion 123 is substantially the same as thediameter of the wall through-hole 54. The rear boss portion 123 isfitted to be slidable from the second wall surface 53 side to the wallthrough-hole 54. The rear boss portion 123 includes an annular rear bosstip surface 123 a.

The rear rotary valve 124 protrudes toward the front rotor 60 from therear boss tip surface 123 a. The two rear rotary valves 124 areseparated in the circumferential direction. Each of the rear rotaryvalves 124 includes a columnar body having a curved innercircumferential surface and a curved outer circumferential surface. Therear rotary valves 124 oppose each other in the direction perpendicularto the direction along which the front rotary valves 122 are arranged.Each of the rear rotary valves 124 is arranged between the two frontrotary valves 122.

The inner circumferential surface of the rear rotary valve 124 is flushwith the inner circumferential surface of the rear boss portion 123, andcontacts the outer circumferential surface of the rotary shaft 12. Theouter circumferential surface of the rear rotary valve 124 is flush withthe outer circumferential surface of the front rotary valves 122. Thelength in the circumferential direction of the rear rotary valves 124 isthe same as the separation distance in the circumferential direction ofthe front rotary valves 122.

As shown in FIG. 8, the rear rotary valve 124 is engaged with the twofront rotary valves 122 in the circumferential direction. The rotaryvalves 122 and 124 pinch each other and are engaged with each other fromthe circumferential direction. The relative positions in thecircumferential direction of the rotors 60 and 80 are specified byengaging the rotary valves 122 and 124 with each other. One connectingvalve 125 is formed by the front rotary valves 122 and the rear rotaryvalve 124. The connecting valve 125 is arranged in the wall through-hole54. The rotary valves 122 and 124 are engaged with each other within thewall through-hole 54.

The connecting valve 125 includes a valve outer circumferential surface125 a having the same diameter as the diameter of the wall through-hole54. The valve outer circumferential surface 125 a is configured by theouter circumferential surfaces of the rotary valves 122 and 124. Sincethe outer circumferential surfaces of the rotary valves 122 and 124 areflush with each other, the valve outer circumferential surface 125 aforms one continuous circumferential surface. The valve outercircumferential surface 125 a contacts the wall inner circumferentialsurface 54 a of the wall through-hole 54. Wall inner circumferentialsurface 54 a is also an inner circumferential surface of theintermediate wall portion 51 formed in ring shape.

The communication mechanism 120 includes a communication passage 130communicates between the compression chambers A4 and A5. Thecommunication passage 130 includes a front-side opening 131, a rear sideopening 132, and a communication groove 133.

As shown in FIG. 8, the front-side opening 131 and the rear side opening132 are formed in the intermediate wall portion 51. The openings 131 and132 are separated in the circumferential directions of the rotors 60 and80. The front-side opening 131 is arranged next to the vane 100. Thefront-side opening 131 is formed in one of the surfaces in thecircumferential direction of the vane 100, i.e., on a surface of thevane 100 located on the opposite side from the rotation direction of therotors 60 and 80. The front-side opening 131 communicates with the vanegroove 110.

As shown in FIGS. 2 and 3, the front-side opening 131 is opened towardthe front compression chamber A4. The front-side opening 131 is formedin the first wall surface 52 in the intermediate wall portion 51, but isnot formed in the second wall surface 53. That is, the front-sideopening 131 does not extend through the intermediate wall portion 51 inthe axial direction Z, and does not directly communicate with the frontcompression chamber A4 and the rear compression chamber A5 to eachother.

The rear side openings 132 is shifted 180 degrees with respect to thefront-side opening 131. Each of the positions of the openings 131 and132 is point symmetric with respect to the central axis of the rotaryshaft 12. The rear side opening 132 is opened toward the rearcompression chamber A5. The rear side opening 132 is formed in thesecond wall surface 53 in the intermediate wall portion 51, but is notformed in the first wall surface 52. That is, the rear side opening 132does not extend through the intermediate wall portion 51 in the axialdirection Z, and does not directly communicate with the frontcompression chamber A4 and the rear compression chamber A5 to eachother.

As shown in FIG. 8, the front-side opening 131 has a half-U shape, andextends in the radial direction R. The rear side opening 132 has ahalf-U shape that is symmetrical to the front-side opening 131. Theshapes of the openings 131 and 132 are not limited to these, and arearbitrary. The communication groove 133 is a part that is recessedoutward in the radial direction of the wall inner circumferentialsurface 54 a. The communication groove 133 extends in thecircumferential direction of the wall inner circumferential surface 54a, and communicates with the opening 131 and 132. The communicationgroove 133 is formed over a half circumference of the wall innercircumferential surface 54 a, so as to connect the openings 131 and 132to each other while bypassing the vane 100. The circumferentialdirection of the wall inner circumferential surface 54 a matches thecircumferential directions of the rotors 60 and 80. Therefore, thecircumferential direction of the wall inner circumferential surface 54 acan also be said to be the circumferential directions of the rotors 60and 80.

According to this configuration, the fluid in the front compressionchamber A4 is moved to the rear compression chamber A5 by passingthrough the front-side opening 131→the communication groove 133→the rearside opening 132. As shown in FIGS. 8 and 9, the inner end surface 103,which is an end face radially inside of the vane 100, contacts the outercircumferential surfaces of the boss portions 121 and 123, and the valveouter circumferential surface 125 a. The outer circumferential surfacesof the boss portions 121 and 123 are flush with each other, the outercircumferential surfaces of the boss portions 121 and 123 are flush withthe valve outer circumferential surface 125 a, and the outercircumferential surfaces of the rotary valves 122 and 124 are flush witheach other. The inner end surface 103 of the vane 100 is a concavesurface that is curved with the same curvature as the outercircumferential surfaces of the boss portions 121 and 123, and the valveouter circumferential surface 125 a. Therefore, the inner end surface103 of the vane 100 comes into surface contact with the outercircumferential surfaces of the boss portions 121 and 123, and the valveouter circumferential surface 125 a.

An outer end surface 104, which is an end face radially outside of thevane 100, is flush with the first part surface 57 a of the rear cylinder50. The outer end surface 104 of the vane 100 contacts the frontcylinder inner circumferential surface 43 of the front cylinder 40. Thevane 100 is sandwiched by the outer circumferential surfaces of the bossportions 121 and 123 and the valve outer circumferential surface 125 a,and the front cylinder inner circumferential surface 43 from the radialdirection R. Accordingly, it is possible to limit the position shift inthe radial direction R of the vane 100. Additionally, it is possible tolimit the fluid from leaking from the boundary part between the vane 100(the inner end surface 103) and the outer circumferential surfaces ofthe boss portions 121 and 123 and the valve outer circumferentialsurface 125 a, or from the boundary part between the vane 100 (the outerend surface 104) and the front cylinder inner circumferential surface43.

Next, using FIGS. 10 and 11, a detailed description is given of thepositional relationship among the introduction port 111, the dischargeport 113, and the openings 131 and 132, and the compression chambers A4and A5.

FIG. 9 is a development view showing the rotors 60 and 80 and the vane100 in the state shown in FIG. 4, and FIG. 10B is a development viewshowing the rotors 60 and 80 and the vane 100 in the state shown in FIG.10A. FIGS. 9 and 10B schematically show the openings 131 and 132 and thecommunication groove 133 provided in the intermediate wall portion 51.

As shown in FIG. 9, the vane 100 does not enter into the front housingchamber A2 in the circumstance in which the vane 100 contacts the secondfront flat surface 72 and the first rear flat surface 91. In this case,the number of the front compression chamber A4 is one, the frontcompression chamber A4 is filled with the suction fluid, and the frontcompression chamber A4 reaches the maximum volume.

In contrast, since a part of the vane 100 enters into the rear housingchamber A3, in the rear housing chamber A3, two rear compressionchambers A5 (a first rear compression chamber A5 a and a second rearcompression chamber A5 b) are formed at either side of the vane 100. Thefirst rear compression chamber A5 a and the second rear compressionchamber A5 b are divided by the contacting part between the second rearflat surface 92 and the second wall surface 53 and the vane 100, andadjacent to each other in the circumferential direction.

The first rear compression chamber A5 a communicates with the rear sideopening 132, and does not communicate with the discharge port 113. Thesecond rear compression chamber A5 b communicates with the dischargeport 113, and does not communicate with the rear side opening 132. Thevane 100 divides the first rear compression chamber A5 a communicatingwith the rear side opening 132 and the second rear compression chamberA5 b communicating with the discharge port 113, so that the rear sideopening 132 does not directly communicate with the discharge port 113.

Thereafter, when the rotary shaft 12 is rotated by the electric motor13, the rotors 60 and 80 are rotated. Then, the vane 100 is moved in theaxial direction Z (the left and right directions in FIG. 9), and a partof the vane 100 enters into the front housing chamber A2. Accordingly,as shown in FIG. 10B, two front compression chambers A4 (a first frontcompression chamber A4 a and second front compression chamber A4 b) areformed in either side of the vane 100. The first front compressionchamber A4 a and the second front compression chamber A4 b are dividedby the contacting part of the second front flat surface 72 and the firstwall surface 52 and vane 100, and adjacent to each other in thecircumferential direction.

The first front compression chamber A4 a communicates with theintroduction port 111, and does not communicate with the front-sideopening 131. The second front compression chamber A4 b communicates withthe front-side opening 131, and does not communicates with theintroduction port 111. The vane 100 divides the first front compressionchamber A4 a communicating with the introduction port 111, and thesecond front compression chamber A4 b communicating with the front-sideopening 131, so that the introduction port 111 and the front-sideopening 131 do not directly communicate with each other. When the rotors60 and 80 are rotated in this state, the volumes of the compressionchambers A4 and A5 are changed. As shown in FIGS. 9 and 10B, the volumeis increased and the suction fluid is drawn in from the introductionport 111 in the first front compression chamber A4 a, and the volume isdecreased and the pumping or compression of the suction fluid isperformed in the second front compression chamber A4 b.

Here, as shown in FIG. 9, the position of the rear side opening 132 is180 degrees different from the position of the front-side opening 131.In the state shown in FIG. 9, the rear side opening 132 is closed withthe second rear flat surface 92. Therefore, the compression chambers A4and A5 are not communicating with each other. Thereafter, when therotors 60 and 80 are rotated, the second front compression chamber A4 band the first rear compression chamber A5 a communicate with each othervia the communication passage 130. Thereafter, as shown in FIG. 16, whenthe second rear flat surface 92 passes the vane 100, the second frontcompression chamber A4 b and the second rear compression chamber A5 bcommunicate with each other via the communication passage 130. Then,when the rear side opening 132 is closed again by the second rear flatsurface 92, the compression chambers A4 and A5 do not communicate witheach other.

The communication mechanism 120 (the communication passage 130) firstmakes the second front compression chamber A4 b and the first rearcompression chamber A5 a communicate with each other, and thereaftermakes the second front compression chamber A4 b and the second rearcompression chamber A5 b communicate with each other. In other words,the communication mechanism 120 makes the front compression chamber A4in the stage where the volume is decreased, and the rear compressionchamber A5 in the stage where the volume is switched from beingincreased to being decreased communicate with each other. Thereafter,when the rotors 60 and 80 are rotated to a position at which the vane100 contacts the second front flat surface 72 and the first rear flatsurface 91, all of the compression fluid in the second front compressionchamber A4 b is discharged from the discharge port 113 via the rearcompression chamber A5. Additionally, the suction fluid drawn into thefirst front compression chamber A4 a is pumped or compressed as thefluid for the second front compression chamber A4 b at the time of thenext rotation of the rotors 60 and 80.

As described above, in the compression chambers A4 and A5, the cyclemovement having two turns (720 degrees) of the rotors 60 and 80 as onecycle is repeated. Accordingly, the suction of the fluid, and thepumping or compression of the fluid are performed.

Although the description has been given by distinguishing between thefront compression chambers A4 a and A4 b, when focusing on the fact thatthe cycle movement having 720 degrees as one cycle is performed in thefront compression chamber A4, the first front compression chamber A4 ais the front compression chamber A4 whose phase is 0 degrees to 360degrees, and the second front compression chamber A4 b is the frontcompression chamber A4 whose phase is 360 degrees to 720 degrees. Thatis, the space formed by the front rotor surface 70, the first wallsurface 52, and the front cylinder inner circumferential surface 43 isdivided into the front compression chamber A4 whose phase is 0 degreesto 360 degrees (a suction stage), and the front compression chamber A4whose phase is 360 degrees to 720 degrees (a pumping or compressionstage) by the vane 100. In other words, the vane 100 generates volumechanges of the first chamber and the second chamber (the volume of thefirst chamber is increased, and the volume of the second chamber isdecreased) with rotations of the rotors 60 and 80, in the state wherethe above-described space is divided into the first chamber into whichthe fluid is drawn in, and the second chamber from which the fluid isdischarged.

The same also applies to the first rear compression chamber A5 a and thesecond rear compression chamber A5 b. That is, it can be said that thefirst rear compression chamber A5 a is the rear compression chamber A5whose phase is 0 degrees to 360 degrees, and the second rear compressionchamber A5 b is the rear compression chamber A5 whose phase is 360degrees to 720 degrees.

Therefore, the communication passage 130 is a passage that makes thefront compression chamber A4 whose phase is 360 degrees to 720 degrees,and the rear compression chamber A5 whose phase is 180 degrees to 540degrees communicate with each other. The first front compression chamberA4 a does not communicate with the rear compression chamber A5. Whenfocusing on this point, the communication mechanism 120 is switched tobe in the non-communicating state when the phase of the frontcompression chamber A4 is 0 degrees to 360 degrees, and to be in thecommunicating state when the phase of the front compression chamber A4is 360 degrees to 720 degrees.

The rear side suction passage 115 communicates with the first rearcompression chamber A5 a. Then, the open/close portion 116 is in theopen state for the time period in which the phase of the rearcompression chamber A5 is 0 degrees to a specific phase. Accordingly,the suction fluid is drawn into the rear compression chamber A5. Thespecific phase is 360 degrees or less, for example. The specific phasewill be described later.

Next, using FIGS. 11A to 11C, a description will be given of a series ofcycle movement of suction/compression performed by the compressionchambers A4 and A5 in the first embodiment. In FIG. 11A, the broken lineindicates the volume change of the front compression chamber A4, theone-dot-chain line indicates the volume change of the rear compressionchamber A5, and the continuous line indicates the substantial volumechange for the combination of the compression chambers A4 and A5, i.e.,the volume change of the entire compressor 10. In FIG. 11A, the longdashed double-short dashed line indicates the pressure change.

As shown in FIG. 11A, the compressor 10 is configured so that the phasedifference is generated by the volume change of the front compressionchamber A4 and the volume change of the rear housing chamber A3.Additionally, the compressor 10 is configured so that the volume changeof the rear compression chamber A5 has a phase lag to the volume changeof the front compression chamber A4. As for the phase difference, therotor surfaces 70 and 90 are curved in the axial direction Z so as tomake the separation distance between them constant, and the volumechanges of the compression chambers A4 and A5 are realized by one vane100. Additionally, the phase difference is realized because the suctionfluid is drawn in when the phase of the rear compression chamber A5 is 0degrees to the specific phase.

As shown in FIGS. 11A and 11B, in the compressor 10, after the suctionof the fluid into the front compression chamber A4 (hereinafter referredto as the suction operation of the front compression chamber A4) isstarted, the open/close portion 116 is in the open state, and thesuction of the fluid into the rear compression chamber A5 (hereinafterreferred to as the suction operation of the rear compression chamber A5)is started. Accordingly, the suction of the fluid is performed in thecompression chambers A4 and A5. Thereafter, when the suction of thefluid is completed by the front compression chamber A4, in which thesuction of the fluid was started first, the volume decrease of the frontcompression chamber A4 is started.

As shown in FIGS. 11A and 11C, the communication mechanism 120 isconfigured to be in the open state at the timing (360 degrees) when thesuction by the front compression chamber A4 ends. Accordingly, thecompression chambers A4 and A5 communicate with each other. Therefore,with the volume decrease of the front compression chamber A4, thesuction fluid in the front compression chamber A4 is pumped to the rearcompression chamber A5 via the communication mechanism 120 (hereinafterreferred to as the pumping operation of the front compression chamberA4). In this stage, the suction operation of the rear compressionchamber A5 is continued.

That is, the pumping operation of the front compression chamber A4 andthe suction operation of the rear compression chamber A5 are performedin the state where the compression chambers A4 and A5 communicate witheach other. In this state, the suction fluid is drawn into the rearcompression chamber A5 from both the front compression chamber A4 andthe rear side suction passage 115. Accordingly, even after the suctionoperation of the front compression chamber A4 is completed, thesubstantial total volume of the compression chambers A4 and A5, i.e.,the volume of the entire compressor 10 continues to be increased.

Thereafter, as shown in FIGS. 11A and 11B, the open/close portion 116 isin the closed state with the specific phase corresponding to the timingat which the volume of the entire compressor 10 reaches its maximum.Accordingly, the suction operation of the rear compression chamber A5 iscompleted, and the compression of the fluid housed in the rearcompression chamber A5 in the rear compression chamber A5 (hereinafterreferred to as the compression operations of the rear compressionchamber A5) is started. Similarly, the compression of the fluid in thefront compression chamber A4 (hereinafter referred to as the compressionoperation of the front compression chamber A4) is also performed. Inthis case, the compression chambers A4 and A5 communicate with eachother. That is, the compressor 10 is configured such that thecompression operations are performed in the compression chambers A4 andA5 in the state where the compression chambers A4 and A5 communicatewith each other. In the following description, the compressionoperations in the compression chambers A4 and A5 in the state where thecompression chambers A4 and A5 communicate with each other is referredto as the parallel compression operation.

Thereafter, the compression operation of the front compression chamberA4 is completed during the compression operation of the rear compressionchamber A5. Then, as shown in FIGS. 11A and 11C, in synchronization withthe completion of the compression operation of the front compressionchamber A4, the communication mechanism 120 becomes thenon-communicating state. After the compression operation of the frontcompression chamber A4 is completed, only the compression operation ofthe rear compression chamber A5 is continued, and when the compressionoperation is completed, one cycle of suction/compression in thecompressor 10 is completed.

That is, the cycle movement performed by the compressor 10 of the firstembodiment is performed in the following order:

(A) the front suction operation in which, in the state where thecompression chambers A4 and A5 do not communicate with each other, whilethe suction operation of the front compression chamber A4 is performed,the suction operation of the rear compression chamber A5 is notperformed;

(B) the parallel suction operation in which the suction operation of thesuction fluid into the compression chambers A4 and A5 is performed;

(C) the communication intermediate operation in which the pumpingoperation of the front compression chamber A4 and the suction operationof the rear compression chamber A5 are performed in the state where thecompression chambers A4 and A5 communicate with each other;

(D) the parallel compression operation; and

(E) the rear compression operation in which, in the state where thecompression chambers A4 and A5 do not communicate with each other, whilethe compression operation of the rear compression chamber A5 isperformed, the compression operation of the front compression chamber A4is not performed. Here, the front suction operation corresponds to thefirst compression chamber suction operation, and the rear compressionoperation corresponds to the second compression chamber compressionoperation.

The operation of the first embodiment will now be described.

As indicated by the continuous line in FIG. 11A, the suction fluid isdrawn into the compression chambers A4 and A5 having mutually differentphases for the volume change. Therefore, the substantial combined volumeof the compression chambers A4 and A5 (the displacement of thecompressor 10) is larger than the case where the front compressionchamber A4 draws in independently. Particularly, even after the volumeof the front compression chamber A4 reaches its maximum, since thevolume is increased for the rear compression chamber A5, the volume ofthe entire compressor 10 is increased.

Thereafter, the communication intermediate operation→the parallelcompression-operations→the rear compression operation are performed.Accordingly, the substantial volume of the compression chambers A4 andA5 is smoothly decreased. Accordingly, the substantial volume change forone cycle forms a smooth waveform with only one peak, instead of awaveform in which two peaks are generated as in the two-step compressionmethod shown in FIG. 12. That is, during one cycle, locally, the volumehardly becomes small. Additionally, as indicated by the long dasheddouble-short dashed line in FIG. 17A, the pressure of the suction fluiddrawn into the compression chambers A4 and A5 is smoothly increased.

The first embodiment has the following advantages

(1-1) The compressor 10 includes the rotary shaft 12, the housing 11 inwhich the, suction port 11 a and the discharge port 11 b are formed, andthat houses the rotary shaft 12, and the compression chamber A4 and A5.The compression chambers A4 and A5 are configured such that the suctionfluid is drawn in and the volume change is periodically caused withrotation of the rotary shaft 12. The phases of volume changes of thecompression chambers A4 and A5 are shifted from each other. In thisconfiguration, the compressor 10 includes the communication mechanism120 that is switched between the communicating state in which thecompression chambers A4 and A5 communicate with each other, and thenon-communicating state in which the compression chamber A4 and A5 donot communicate with each other. The compressor 10 repeats the cyclemovement including the parallel compression operation in which thecompression operation of the fluid in the compression chambers A4 and A5is performed with the communication mechanism 120 in the communicatingstate.

According to this configuration, since the suction fluid is drawn intothe compression chambers A4 and A5, compared with the configuration inwhich the suction fluid is drawn into only one of the compressionchambers, the displacement of the compressor 10 is improved.Additionally, since the cycle movement including the parallelcompression operation is performed, locally, the volume of the entirecompressor 10 hardly becomes small. For example, in the stage where theparallel compression operation are performed, the suction operation ofthe rear compression chamber A5 is already completed. Therefore, in thestage where the compression operation of the front compression chamberA4 is completed, the suction operation of the rear compression chamberA5 hardly occurs. Accordingly, it is possible to reliably compress thefluid by using the two compression chambers A4 and A5.

(1-2) The compression chambers A4 and A5 are opposed to each other inthe axial direction Z. According to this configuration, compared withthe configuration in which the compression chambers A4 and A5 arearranged to be opposed to each other in the radial direction R, it ispossible to limit an increase in the size of the compressor 10 in theradial direction R.

(1-3) The cycle movement includes the parallel suction operation, andthe parallel compression operation performed after the parallel suctionoperation. According to this configuration, the volume change of theentire compressor 10 in one cycle movement becomes smooth, and theefficiency is improved.

(1-4) The cycle movement includes the front suction operation (the firstcompression chamber suction operation) performed before the parallelsuction operation, and the rear compression operation performed afterthe parallel compression operation. According to this configuration, asindicated by the continuous line in FIG. 11A, the volume of the entirecompressor 10 can be continuously changed. Accordingly, the efficiencyis further improved.

(1-5) The cycle movement includes the communication intermediateoperation in which the pumping operation from the front compressionchamber A4 to the rear compression chamber A5, and the suction operationof the rear compression chamber A5 are performed under the circumstancewhere the compression chambers A4 and A5 communicate with each other.According to this configuration, since the parallel compressionoperation are performed via the communication intermediate operation,the pressure of the suction fluid that is being drawn into thecompression chambers A4 and A5 can be smoothly increased. Particularly,as indicated by the long dashed double-short dashed line in FIG. 11A,the pressure of the fluid can be smoothly and sequentially increased.Accordingly, the loss can be limited, and the efficiency is furtherimproved.

(1-6) The compressor 10 includes the rotors 60 and 80 that are opposedto each other in the axial direction Z and are rotated with rotation ofthe rotary shaft 12, and cylinders 40 and 50 that include the cylinderinner circumferential surfaces 43 and 56 opposed to the rotor outercircumferential surfaces 62 and 82 in the radial direction R and housethe rotors 60 and 80, respectively. The rotors 60 and 80 include rotorsurfaces 70 and 90 formed into ring shapes, respectively. The compressor10 includes the intermediate wall portion 51 that is arranged betweenthe rotors 60 and 80, and includes wall surfaces 52 and 53 opposed tothe rotor surfaces 70 and 90 in the axial direction Z, and the vane 100that contacts the rotor surfaces 70 and 90 in the state where the vane100 is inserted in the vane groove 110 of the intermediate wall portion51, and is moved in the axial direction Z with rotation of the rotors 60and 80.

The rotor surfaces 70 and 90 include curving surfaces 73 and 93 that arecurved in the axial direction Z so as to be displaced in the axialdirection Z in accordance with their angular positions, respectively.The compression chambers A4 and A5 are formed by the rotor surfaces 70and 90, the wall surfaces 52 and 53, and the cylinder innercircumferential surfaces 43 and 56. The vane 100 that is moved in theaxial direction Z with rotation of the rotors 60 and 80 changes thevolumes of the compression chambers A4 and A5. The rotor surfaces 70 and90 are opposed to each other in the axial direction Z, with theintermediate wall portion 51 being arranged therebetween. Additionally,the separation distance between the rotor surfaces 70 and 90 is constantirrespective of the angular positions of the rotor surfaces 70 and 90including the curving surfaces 73 and 93.

According to this configuration, when the rotors 60 and 80 are rotated,the vane 100 is moved in the axial direction Z in the state where thevane 100 contacts the rotor surfaces 70 and 90, and the volume change ofthe compression chambers A4 and A5 is caused. Accordingly, it ispossible to perform suction and compression in the compression chambersA4 and A5, without providing an exclusive vane for each of thecompression chambers A4 and A5. Additionally, the separation distancebetween the rotor surfaces 70 and 90 including the curving surfaces 73and 93, respectively, is constant irrespective of their angularpositions. Accordingly, the vane 100 is prevented from being separatedfrom either of the rotor surfaces 70 and 90, or that the vane 100 iscaught between the rotor surfaces 70 and 90, when the rotors 60 and 80are rotated.

Here, since the separation distance between the rotor surfaces 70 and 90is constant irrespective of the angular positions, when the frontcurving surface 73 and the rear curving surface 93 are moved fromcertain angular positions to another angular positions, the frontcurving surface 73 gradually approaches the first wall surface 52, andthe rear curving surface 93 is separated from the second wall surface53. Accordingly, the phase difference is generated in the volume changesof the compression chambers A4 and A5. Then, the above-described cyclemovement can be realized by making the suction fluid drawn into each ofthe compression chambers A4 and A5 in which the above-described phasedifference in the volume change is generated. Accordingly, it ispossible to realize a continuous volume change by utilizing thecharacteristic obtained by adopting the above-described configuration.The separation distance between the rotor surfaces 70 and 90 beingconstant irrespective of the angular positions of the rotor surfaces 70and 90 means that some errors are included when the rotors 60 and 80 canbe rotated in the state where the vane ends 101 and 102 contact thecurving surfaces 73 and 93, respectively.

(1-7) the vane ends 101 and 102 are not intermittent, and continuouslycontact the rotor surfaces 70 and 90. That is, the vane ends 101 and 102slide with respect to the rotor surfaces 70 and 90. According to thisconfiguration, the sound is hardly generated when the vane ends 101 and102 hit the rotor surfaces 70 and 90. Therefore, the quietness isimproved.

(1-8) The front rotor surface 70 includes the front flat surfaces 71 and72 that are arranged to be mutually shifted in the axial direction Z.The second front flat surface 72 contacts the first wall surface 52. Thefront curving surface 73 connects the front flat surfaces 71 and 72. Therear rotor surface 90 includes the rear flat surfaces 91 and 92 that arearranged to be mutually shifted in the axial direction Z. The secondrear flat surface 92 contacts the second wall surface 53. The rearcurving surface 93 connects the rear flat surfaces 91 and 92. The firstfront flat surface 71 and the second rear flat surface 92 are opposed toeach other, and the second front flat surface 72 and the first rear flatsurface 91 are opposed to each other.

According to this configuration, the communication between the frontcompression chamber A4 (the first front compression chamber A4 a) on theside on which suction is performed, and the front compression chamber A4(the second front compression chamber A4 b) on the side on whichcompression is performed is restricted by the contact between the secondfront flat surface 72 and the first wall surface 52. Accordingly, theleakage of the fluid can be limited, and the efficiency is improved.Additionally, the first rear flat surface 91 is arranged at a positionopposed to the second front flat surface 72, so as to correspond to thesecond front flat surface 72. Therefore, the separation distance betweenthe first rear flat surface 91 and the second front flat surface 72becomes constant, a trouble hardly occurs in the movement of the vane100, and a gap between the vane 100 and the rotor surfaces 70 and 90 ishardly generated. The same also applies to the rear compression chamberA5.

(1-9) The compressor 10 includes the housing 11 in which the rotaryshaft 12 is housed, and two radial bearings 32 and 34 that support theopposite ends of the rotary shaft 12 in the housing 11 in a rotatablestate. According to this configuration, both ends of the rotary shaft 12are rotationally supported by the radial bearings 32 and 34. Therefore,compared with a scroll compressor in which only one end of the rotaryshaft 12 is supported by a radial bearing, it is possible to stablysupport the rotary shaft 12. Accordingly, this configuration can respondto high speed rotation.

Second Embodiment

A second embodiment is different from the first embodiment in theconfiguration of the communication mechanism and the cycle movement. Thedifferences are described below.

As shown in FIGS. 12 and 13, a communication mechanism 150 of the secondembodiment includes two front rotary valves 151 and a rear rotary valve152. The two front rotary valves 151 have sectoral shapes, and areseparated in the circumferential direction. The rear rotary valve 152 issandwiched between the front rotary valves 151. A connecting valve 153does not have a closed ring shape, and has a sectoral shape. Therefore,an open space 154 where fluid can move is formed in the wallthrough-hole 54, particularly, between the rotary shaft 12 and the wallinner circumferential surface 54 a. The connecting valve 153 includes avalve outer circumferential surface 153 a contacting the wall innercircumferential surface 54 a.

The front-side opening 155 is opened to the front compression chamber A4and to the radially inside of the wall through-hole 54. The rear sideopening 156 is opened to the rear compression chamber A5 and to theradially inside of the wall through-hole 54. The rear side opening 156is arranged closer to the front-side opening 155 than the position thatis point symmetric with respect to the front-side opening 155. That is,the openings 155 and 156 are arranged with an angle interval smallerthan 180 degrees. The communication groove 157 of the second embodimentis formed between the openings 155 and 156 of the wall innercircumferential surface 54 a. The communication groove 157 communicateswith the open space 154 and the rear side opening 156, and thecommunication groove 157 is separated from the front-side opening 155.Therefore, there is a groove-less surface 158 in the part between theopenings 155 and 156 in the wall inner circumferential surface 54 a.

FIG. 12 shows a case where the connecting valve 153 is arranged radiallyinside of the front-side opening 155. In this case, the valve outercircumferential surface 153 a closes the opening part that is radiallyinside of the front-side opening 155. Accordingly, the inflow of thefluid that goes to the communication groove 157 from the front-sideopening 155 is restricted. Accordingly, the compression chambers A4 andA5 are in the non-communicating state in which they do not communicatewith each other. Especially, when the valve outer circumferentialsurface 153 a contacts the groove-less surface 158, the leakage of thefluid from the front-side opening 155 to the communication groove 157 isrestricted.

FIG. 13 shows a case where the connecting valve 153 is moved in thecircumferential direction of the rotors 60 and 80 with respect to thefront-side opening 155, with rotation of the rotors 60 and 80. In thiscase, the connecting valve 153 does not close the opening part that isradially inside of the front-side opening 155. Accordingly, the inflowof the fluid that goes to the communication groove 157 from thefront-side opening 155 via the open space 154 is permitted. Accordingly,the fluid in the front compression chamber A4 (the second frontcompression chamber A4 b) passes through the front-side opening 155→theopen space 154→the communication groove 157→the rear side opening 156,and moves to the rear compression chamber A5. Accordingly, thecompression chambers A4 and A5 are in the communicating state in whichthey communicate with each other.

The connecting valve 153 is moved between the closed position at whichthe front-side opening 155 is closed and the open position at which thefront-side opening 155 is opened, in accordance with the angularpositions of the rotors 60 and 80. At the open position, the front-sideopening 155 communicates with the communication groove 157 via the openspace 154. In other words, the communication mechanism 150 of the secondembodiment is switched between the communicating state and thenon-communicating state during one rotation of the rotors 60 and 80.

In the above-described configuration, the communication period of thefront compression chamber A4 and the rear compression chamber A5 in onecycle of rotation of the rotors 60 and 80 is defined by the length inthe circumferential direction of the valve outer circumferential surface153 a (the angle range occupied by the connecting valve 153).Additionally, the timing at which the compression chambers A4 and A5communicate with each other in one cycle of rotation of the rotors 60and 80 is defined by the angular position of the connecting valve 153.Accordingly, when the angular position of the connecting valve 153, orthe length in the circumferential direction of the valve outercircumferential surface 153 a is adjusted, the timing at which thecompression chambers A4 and A5 communicate with each other and theperiod for communication are adjusted.

Next, using FIGS. 14A to 14C, a description will be given of the cyclemovement of the second embodiment, together with the states of theopen/close portion 116 and the communication mechanism 150.

As shown in FIGS. 14A to 14C, the cycle movement of the secondembodiment also includes the front suction operation and the parallelsuction operation. In the second embodiment, as shown in FIG. 14C, thecommunication mechanism 150 is in the non-communicating state in thecompletion stage of the suction operation of the front compressionchamber A4, and thereafter maintains the non-communicating state.Accordingly, as shown in FIG. 14A, the compression operation of thefront compression chamber A4 is performed after the completion of thesuction operation of the front compression chamber A4. In contrast, thesuction operation of the rear compression chamber A5 is continued evenafter the completion of the suction operation of front compressionchamber A4.

Thereafter, as shown in FIG. 14B, the open/close portion 116 is in theclosed state in the middle of the compression operation of the frontcompression chamber A4. Accordingly, the suction operation of the rearcompression chamber A5 is completed, and the compression operation isperformed. Additionally, the communication mechanism 150 is in thecommunicating state at the timing at which the open/close portion 116 isin the closed state. Accordingly, the volume of the entire compressor 10is the combined volume of the compression chambers A4 and A5. Incontrast, when the compression chambers A4 and A5 communicate with eachother, the pressures of the compression chambers A4 and A5 are smoothed.Accordingly, as indicated by the long dashed double-short dashed line inFIG. 14A, the pressure is temporarily decreased. Thereafter, thecompressor 10 performs the parallel compression operation. Thecompressor 10 performs the rear compression operation after the parallelcompression operation. Accordingly, one cycle movement is completed.

That is, the cycle movement of the second embodiment is performed in theorder of:

(A) the front suction operation;

(B) the parallel suction operation;

(C) the non-communicating intermediate operation in which thecompression operation of the front compression chamber A4 and thesuction operation of the rear compression chamber A5 are performed inthe state where the compression chambers A4 and A5 are not communicatingwith each other;

(D) the parallel compression operation; and

(E) the rear compression operation.

As described above, according to the second embodiment, instead of theadvantages of (1-5), the following operations and advantages areobtained.

(2-1) The cycle movement includes the non-communicating intermediateoperation performed between the parallel suction operation and theparallel compression operation. In the non-communicating intermediateoperation, under the circumstance where the compression chambers A4 andA5 are not communicating with each other, the compression operation ofthe front compression chamber A4 and the suction operation of the rearcompression chamber A5 are performed. According to this configuration,the pumping of the fluid from the front compression chamber A4 to therear compression chamber A5 is not performed. Accordingly, it ispossible to limit a decrease in the displacement of the compressor 10due to the pumping. To be more specific, when the pumping of the fluidfrom the front compression chamber A4 to the rear compression chamber A5is performed, a part of the suction fluid in the front compressionchamber A4 is drawn in by the rear compression chamber A5. Therefore,the amount of the fluid drawn in from the rear side suction passage 115is decreased. Accordingly, the displacement of the compressor 10 isdecreased. In contrast, in the second embodiment, since the pumping ofthe fluid from the front compression chamber A4 to the rear compressionchamber A5 is not performed, it is possible to fill the rear compressionchamber A5 with the suction fluid drawn in from the rear side suctionpassage 115. Accordingly, it is possible to limit a decrease in thedisplacement of the compressor 10.

The above-described embodiments may be modified as follows. Theabove-described embodiments and the following modifications can becombined as long as the combined modifications remain technicallyconsistent with each other.

The open/close portion 116 may be in the open state or the closed statein the circumstance where the vane 100 contacts either of the rear flatsurfaces 91 and 92. The open/close portion 116 may be omitted.

The compression chambers A4 and A5 may communicate with each otherduring the parallel suction operation.

The rear rotor 80 may have a larger diameter than the front rotor 60.

Although the rotors 60 and 80 have different diameters, this is not alimitation, and may have the same diameter. That is, the volumes of thecompression chambers A4 and A5 may be the same. In other words, the rearcompression chamber A5 may be the first compression chamber, and thefront compression chamber A4 may be the second compression chamber.

The front flat surfaces 71 and 72 and the rear flat surfaces 91 and 92may be omitted. That is, the entire rotor surfaces 70 and 90 may becurving surfaces.

The first vane end 101 and the front rotor surface 70 are not limited tothe configuration in which they contact each other over the entire partfrom the radially inner end to the radially outer end, and may beconfigured to contact each other over a partial range in the radialdirection. Additionally, the first vane end 101 and the front rotorsurface 70 are not limited to the configuration in which they contacteach other over the entire circumference, and may be configured tocontact each other over a partial angular range. The same applies to thesecond vane end 102 and the rear rotor surface 90.

The number of the vane 100 is arbitrary, and may be plural, for example.Additionally, the circumferential direction position of the vane 100 isarbitrary.

The shapes of the vane 100 and the vane groove 110 are not limited tothose in each of the embodiments, as long as the shapes allow themovement of the vane 100 in the axial direction Z, while the movement inthe circumferential direction is restricted. For example, the vane mayhave a sectoral shape.

Additionally, the vane may be configured to move in the axial directionZ like a pendulum that moves about a predetermined place. That is, thevane may be configured to move in the axial direction Z in accordancewith rotational movement, and not limited to linear movement.

The specific shapes of the cylinders 40 and 50 are arbitrary. Forexample, the bulged part 46 may be omitted. Additionally, though thecylinders 40 and 50 are different bodies, they may be integrally formed.

Similarly, the specific shapes of the housings 21 and 22 are alsoarbitrary.

The cylinders 40 and 50 may be omitted. In this case, the innercircumferential surface of the housing 11 may form the compressionchambers A4 and A5. In this configuration, the housing 11 corresponds tothe first cylindrical portion and the second cylindrical portion.

The electric motor 13 and the inverter 14 may be omitted. That is, theelectric motor 13 and the inverter 14 are not essential in thecompressor 10.

The rotors 60 and 80 may be each fixed to the rotary shaft 12 so as tobe integrally rotated with the rotary shaft 12, or only one of therotors 60 and 80 may be attached to the rotary shaft 12 to be integrallyrotated with the rotary shaft 12, and the other may be attached to therotary shaft 12 to be rotatable with respect to the rotary shaft 12.Even in this case, since the rotary valves 122 and 124 are engaged witheach other in the circumferential direction, with the rotation of one ofthe rotors 60 and 80, the other is also rotated.

The outer circumferential surfaces of the boss portions 121 and 123 arenot flush, and have stepped shapes. In this case, the inner end surface103 of the vane 100 may similarly have a stepped shape, so that a gap isnot formed.

The configuration of the communication mechanism that makes thecompression chambers A4 and A5 communicate with each other is arbitrary.For example, as shown in FIGS. 15 and 16, the communication mechanism200 may be formed so as to bypass the intermediate wall portion 51. Forexample, the communication mechanism 200 may make the compressionchambers A4 and A5 communicate with each other via the communicationpassage 201 formed in the cylinder side wall portions 42 and 55. Thecommunication passage 201 includes a front-side opening formed in thepart corresponding to the second front compression chamber A4 b of thefront cylinder inner circumferential surfaces 43, and a rear sideopening formed in the part corresponding to the first rear compressionchamber A5 a of the rear cylinder inner circumferential surfaces 56, andconnects the openings to each other. In this case, the communicationmechanism 200 is switched to the non-communicating state when the phaseof the front compression chamber A4 is 0 degrees to 360 degrees, and tothe communicating state when the phase of the front compression chamberA4 is 360 degrees to 720 degrees.

In this case, the boss portions 121 and 123 and the rotary valves 122and 124 may be omitted. That is, it is not essential that the rotors 60and 80 contact or engage with each other. In this configuration, thediameter of the wall through-hole 54 may be reduced, so that the wallinner circumferential surface 54 a and the rotary shaft 12 contact or beclose to each other. Additionally, the inner end surface 103 of the vane100 may directly contact the rotary shaft 12.

The configuration for drawing the suction fluid into the rearcompression chamber A5 is arbitrary. For example, as shown in FIG. 17, arear side suction port 211 through which the suction fluid is drawn inmay be provided in the housing 11 separately from the suction port 11 a,for example. In this case, the compressor 10 may include a rear sidecommunication mechanism 212 that is switched between the communicatingstate in which the rear side suction port 211 and the rear compressionchamber A5 communicate with each other, and the non-communicating state.

The configuration of the rear side communication mechanism 212 isarbitrary, and the following configuration may be considered.

As shown in FIG. 17, the rear side communication mechanism 212 includesa rear side suction port 213 formed in the rear rotor 80, acommunication port 214 provided on the rear housing member 22 side withrespect to the rear rotor 80 and communicates with the rear side suctionport 213, and a passage 215 connecting the rear side suction port 211with the communication port 214.

The rear side suction port 213 communicates with the first rearcompression chamber A5 a. Particularly, an open end that is opened tothe rear rotor surface 90 of the rear side suction port 213 is providedin a side part of the second rear flat surface 92 located on theopposite side from the discharge port 113.

An open end on the opposite side from the open end on the rear rotorsurface 90 in the rear side suction port 213 is formed at a positionopposed to a boss 216 that contacts the bottom surface of the rear rotor80. The communication port 214 is formed in the boss 216, and extends inthe circumferential direction so as to be overlapped with the rotationlocus of the open end on the above-described opposite side from the rearside suction port 213 when seen from the axial direction Z.

The length and position in the circumferential direction of thecommunication port 214 are configured to correspond to the rotation ofthe rear side suction port 213, so that the communication port 214communicates with the rear side suction port 213 at a desired suctionstart timing, and does not communicate with the rear side suction port213 at a desired suction completion timing. Accordingly, the boss 216closes the rear side suction port 213 in the state where the rear sidesuction port 213 and the communication port 214 do not communicate witheach other.

The above-described configuration is not a limitation, and the rear sidesuction passage 115 that makes the rear side suction port 211 and thefirst rear compression chamber A5 communicate with each other may besimply provided in the cylinders 40 and 50 and the housing 11.Accordingly, the suction fluid is drawn in for the period during whichthe phase of the rear compression chamber A5 is 0 degrees to 360degrees.

The configuration may be used in which the rotary valves 122 and 124 areomitted, and the boss tip surfaces 121 a and 123 a directly contact eachother. That is, the rotary valves 122 and 124 are not essential.

As long as the openings 131 and 132 are mutually separated in thecircumferential direction, their specific positions are arbitrary.

The suction operation of the front compression chamber A4 may be startedafter the suction operation of the rear compression chamber A5 isstarted. In this case, the compression operation of the frontcompression chamber A4 may be completed after the compression operationof the rear compression chamber A5 is completed.

The parallel suction operation may be omitted. In this case, the periodmay be adjusted in which the suction operations of the compressionchambers A4 and A5 are performed, so that the parallel compressionoperation may be performed.

The compressor 10 may be used for devices other than an air-conditioner.For example, the compressor 10 may be used to supply compressed air to afuel cell mounted in a fuel cell vehicle.

The compressor 10 may be mounted on any structure other than a vehicle.

The fluid to be compressed by the compressor 10 is not limited torefrigerant including oil, and is arbitrary.

The present disclosure is applicable to a compressor that includes atleast two compression chambers having mutually different phases for thevolume change. For example, the present disclosure may be also appliedto a Rotasco compressor.

1. A compressor comprising: a rotary shaft; a housing housing the rotaryshaft and having a suction port through which a suction fluid is drawnin and a discharge port through which a compression fluid is discharged;a first compression chamber and a second compression chamber formed tointroduce therein the suction fluid, respective volumes of the firstcompression chamber and the second compression chamber beingperiodically changed with rotation of the rotary shaft, and phases ofchanges of the respective volumes being mutually shifted; and acommunication mechanism switched between a communicating state in whichthe first compression chamber and the second compression chambercommunicate with each other, and a non-communicating state in which thefirst compression chamber and the second compression chamber do notcommunicate with each other, wherein a cycle movement is performed thatincludes parallel compression operation in which compression of fluid isperformed in the compression chambers in the communicating state.
 2. Thecompressor according to claim 1, wherein the first compression chamberand the second compression chamber are opposed to each other in theaxial direction of the rotary shaft.
 3. The compressor according toclaim 1, wherein the cycle movement includes a parallel suctionoperation in which a suction operation of the suction fluid into thecompression chambers is performed, and the parallel compressionoperation performed after the parallel suction operation.
 4. Thecompressor according to claim 3, wherein the cycle movement includes acommunication intermediate operation performed between the parallelsuction operation and the parallel compression operation, and in thecommunication intermediate operation, under a circumstance where thecommunication mechanism is in the communicating state, a pumpingoperation moving the fluid in the first compression chamber to thesecond compression chamber with a volume decrease of the firstcompression chamber, and a suction operation of the suction fluid intothe second compression chamber are performed.
 5. The compressoraccording to claim 3, wherein the cycle movement includes anon-communicating intermediate operation performed between the parallelsuction operation and the parallel compression operation, and in thenon-communicating intermediate operation, under a circumstance where thecommunication mechanism is in the non-communicating state, a compressionoperation of the fluid in the first compression chamber and a suctionoperation of the suction fluid into the second compression chamber areperformed.
 6. The compressor according to claim 1, further comprising: afirst rotor including a ring-shaped first rotor surface, and rotatedwith rotation of the rotary shaft; a second rotor opposed to the firstrotor in an axial direction of the rotary shaft, rotated with therotation of the rotary shaft, and including a ring-shaped second rotorsurface; a first cylindrical portion including a first innercircumferential surface opposed to an outer circumferential surface ofthe first rotor in a radial direction of the rotary shaft, and housingthe first rotor; a second cylindrical portion including a second innercircumferential surface opposed to an outer circumferential surface ofthe second rotor in the radial direction, and housing the second rotor;a wall portion arranged between the rotors, and including a first wallsurface opposed to the first rotor surface in the axial direction, and asecond wall surface opposed to the second rotor surface in the axialdirection; and a vane contacting the rotor surfaces in a state where thevane is inserted into a vane groove formed in the wall portion, andmoving in the axial direction with rotation of the rotors, wherein thefirst rotor surface includes a first curving surface curved in the axialdirection so as to be displaced in the axial direction in accordancewith its angular position, the second rotor surface includes a secondcurving surface curved in the axial direction so as to be displaced inthe axial direction in accordance with its angular position, the firstcompression chamber is formed by the first rotor surface, the first wallsurface, and the first inner circumferential surface, the volume of thefirst compression chamber being changed by the vane with rotation of thefirst rotor, the second compression chamber is formed by the secondrotor surface, the second wall surface, and the second innercircumferential surface, the volume of the second compression chamberbeing changed by the vane with rotation of the second rotor, the rotorsurfaces are opposed to each other in the axial direction with the wallportion being arranged therebetween, and a separation distance betweenthe rotor surfaces including the curving surfaces is constantirrespective of their angular positions.
 7. The compressor according toclaim 6, wherein the first rotor surface includes a first flat surfaceseparated from the first wall surface in the axial direction, andperpendicular to the axial direction, and a second flat surface that isa surface separated from the first flat surface in a circumferentialdirection, and perpendicular to the axial direction, and that contactsthe first wall surface, and the first curving surface connects the firstflat surface with the second flat surface, and is curved in the axialdirection so as to gradually approach the first wall surface from thefirst flat surface to the second flat surface.
 8. The compressoraccording to claim 1, wherein the cycle movement includes a firstcompression chamber suction operation performed before the parallelsuction operation, and in the first compression chamber suctionoperation, in a circumstance where the communication mechanism is in thenon-communicating state, a suction operation of the suction fluid intothe first compression chamber is performed, and a suction operation ofthe suction fluid into the second compression chamber is not performed.9. The compressor according to claim 1, wherein the cycle movementincludes a second compression chamber compression operation performedafter the parallel compression operation, and in the second compressionchamber compression operation, under a circumstance where thecommunication mechanism is in the non-communicating state, a compressionoperation of the fluid in the second compression chamber is performed,and a compression operation of the fluid in the first compressionchamber is not performed.